含有空值的多值依赖强保持条件的进一步研究

A Further Study of Strong Hold Conditions of Multivalued Dependencies With Null Values

本文对含有空值的多值依赖的强保持条件进行了深入讨论，对文［１］、［２］中的相应概念做了根本的修正。提出了新的含有空值的多值依赖强保持条件，论证了它的正确性。从而为进一步讨论不完全关系的理论和应用提供了一个可靠的条件。

In this paper, strong hold condition of multivalue dependencies with null value is discussed deeply, and the corresponding concepts in literature [1] and [2] are modified fundamentally.New strong hold condition of multivalue with null value is presented, and its validity is proved.